chore: add constructor formatter

tooling/nargo_fmt/src/visitor/expr.rs

@@ -39,6 +39,18 @@
                     self.format_expr(infix.rhs)
                 )
             }
+            ExpressionKind::Constructor(constructor_expr) => {
+                let type_str = constructor_expr.type_name.to_string();
+                let formatted_fields = constructor_expr
+                    .fields
+                    .iter()
+                    .map(|(field_ident, field_value)| {
+                        format!("{}: {}", field_ident, self.format_expr(field_value.clone()))
+                    })
+                    .collect::<Vec<_>>()
+                    .join(", ");
+                format!("{} {{ {} }}", type_str, formatted_fields)
+            }
             ExpressionKind::Literal(literal) => match literal {
                 Literal::Integer(_) => slice!(self, span.start(), span.end()).to_string(),
                 Literal::Array(ArrayLiteral::Repeated { repeated_element, length }) => {
@@ -96,7 +108,7 @@
         if let Some(first_stmt) = block.first() {
             let slice = slice!(self, self.last_position, first_stmt.span.start());
             let len =
                 slice.chars().take_while(|ch| ch.is_whitespace()).collect::<String>().rfind('\n');
             self.last_position += len.unwrap_or(0) as u32;
         }
     }

tooling/nargo_fmt/tests/expected/constructor.nr

@@ -0,0 +1,8 @@
+struct Point {
+    x: i32,
+    y: i32,
+}
+
+fn foo() {
+    Point { x: 5, y: 10 };
+}

tooling/nargo_fmt/tests/input/constructor.nr

@@ -0,0 +1,8 @@
+struct Point {
+    x: u8,
+    y: u8,
+}
+
+fn foo() {
+    Point{x :5,y:  10   };
+}